|This article belongs to the Classic Continuity|
Duped is the second episode of Ben 10: Ultimate Alien.
Two Forever Knights try to invade the local museum using an alien paramilitary tank, but they're interrupted by Ben as Rath. Before he can fight them, Gwen calls Rath and tells him that he's missing Julie's tennis game. After this, Rath sees the Forever Knights running away, gets angry, and tears apart their tank, then heads to the stadium for Julie's game.
When Julie is about to begin her match, Ben shows up and draws attention to himself, blowing her concentration in the process. Julie and Gwen get mad at Ben for showing up late. Kevin wants to investigate why the Forever Knights tried to rob the museum, but Gwen disagrees on going, stating that they're probably stealing some tech to rule the Earth. Ben also wants to catch the Sumo Slammers movie, but Gwen tells him not to. She tells Ben he can't be in two places at once.
Ben then comes up with a plan. He hides in the bathroom and transforms into Echo Echo and splits into three, then transforms back with his clones doing the same and there are now three Ben Tennysons. One of them is the "normal" Ben, the second is a "sensitive" Ben, and the third is an "arrogant" Ben. However, he doesn't know this. The normal Ben goes to the Sumo Slammers 3-D movie, the sensitive Ben goes with Kevin to investigate the Forever Knights robbery, and the arrogant Ben stays to watch Julie's match.
Meanwhile, the Forever Knights, and their king Urien go through a sewer and blow up a wall, creating a tunnel that they enter.
Unfortunately at the match, the arrogant Ben makes loud comments that distracts Julie and does loud interviews. He also flirts with other girls, angering Gwen and Julie. Meanwhile, Kevin and the sensitive Ben arrive at the museum, where Sensitive Ben talks about his feelings and their past and friendship, which annoys and weirds out Kevin. Back at the match, Gwen yells at Arrogant Ben for being a jerk and he loudly says that Julie is supposed to lose. Meanwhile, the normal Ben is enjoying the Sumo Slammers movie.
The Forever Knights are still burrowing under the museum and one of them plants a device at Urien's behest. An explosion rocks the museum and Kevin recognizes the device. Sensitive Ben transforms into Humungousaur and the ground collapses beneath him and Kevin.
They fall into where the Forever Knights are located and the Forever Knights attack. Humungousaur says that the Knights are being hurtful and Kevin tells him to do something, but Humungousaur says that they should work towards a common plan and Kevin tells him to throw him. He does and knocks out the Forever Knights. As they continue on, Humungousaur hits his head and transforms back into Sensitive Ben.
Urien gets to the artifact he is looking for, which is a jewel, and takes it. Sensitive Ben tells him not to touch the exhibits, even holding up a sign which disgusts Kevin. While they argue, Urien uses the jewel to activate a suit of ancient robotic armor, Toltech Battle Armor, that envelops him and he attacks Sensitive Ben and Kevin in his new battle suit. While Kevin fights Urien, Sensitive Ben calls the other Bens. They both run to help, with Arrogant Ben disappointing Julie when he leaves.
The other Bens arrive just as Kevin and Sensitive Ben come running out of the museum. When Kevin sees all three Bens, he demands that they explain the situation to him before Urien comes crashing out. The three Bens activate their Ultimatrixes: Normal Ben transforms into Big Chill, Arrogant Ben transforms into Murk Upchuck, and Sensitive Ben transforms into Cannonbolt. The three aliens attack Urien, but they ultimately get in each others' way and are defeated. While Kevin holds off Urien, they all transform into Echo Echo and merge into one. Echo Echo then transforms back into Ben just as Kevin is thrown towards him by Urien.
Ben then transforms into Lodestar and magnetises the armor, causing several metal objects to fly at it (including Kevin's Car, which makes Kevin faint). Lodestar then tears the armor apart with his magnetism. The pieces of the armor fall on Urien, defeating him, before Lodestar transforms back into Ben.
Back at the stadium, Ben apologizes to Julie for not being present at the match. Even though Julie won the tournament, she was upset at Ben thanks to his arrogant clone embarrassing her. She kindly asks Ben to make it up for her by taking her to see the Sumo Slammers 3-D movie to make up for it, but Ben mentions that he saw it during the match, which causes Julie to be very furious. She and Gwen storm off in disgust along with Kevin, leaving Ben all alone to repent for what he has done in order to gain back their trust.
- A third faction of Forever Knights appear, this time led by Urien.
- Julie wins the Tennis Championship.
- Ben uses an alien to be in several places at once for the second time. The first time was in Divided We Stand with Ditto.
Ultimatrix Alien Debuts
- Rath (Ultimate Alien debut)
- Echo Echo (Ultimate Alien debut)
- Murk Upchuck (Ultimate Alien debut)
- Big Chill (Ultimate Alien debut)
- Cannonbolt (Ultimate Alien debut)
- Lodestar (Ultimate Alien debut)
- Ben's middle name is revealed to be Kirby.
- Forever Knights (first re-appearance)
- Urien (first appearance)
By Normal Ben:
- Rath (first re-appearance; off-screen transformation)
- Echo Echo (x2; first re-appearance)
- Big Chill (first re-appearance)
- Lodestar (first re-appearance)
By Sensitive Ben:
By Arrogant Ben:
Naming and Translations
- When Gwen asks Arrogant Ben about his attitude, he replies "I'm Ben classic", a reference to his personality in the original series and the third season of Alien Force.
- This episode is the 100th episode overall of the franchise.
- If Ben had told Arrogant Ben to go with Kevin and Sensitive Ben to Julie's game, there probably wouldn't have been any problems.
- An episode of Static Shock shares the same title and has also been written by Len Uhley.